At sudden temperature changes (“temperature shocks”), e.g., during immersion of the measuring or monitoring device into the measuring medium, these joints are frequently exposed to extreme mechanical stresses due to the different temperature coefficients and the associated different expansion behavior of the (ceramic and metallic) materials involved. This may result in cracking of the joints, for example.
Therefore, high demands are placed on the joints in practice with regard to reliability, durability, long-term stability, and tightness. The long-term-stable tightness in particular is of substantial importance, since gases, liquids, or foreign particles, which undesirably intrude from the outside due to leakages (cracking), may result in damage or even destruction of the (measuring) device.
High-grade joints between ceramic and metallic components are generally known. US 2002/0139563 A1 describes a joint between a metallic connection and a ceramic substrate using a melted interim layer made of a foil containing indium. Manufacturing this joint is very expensive from the processing point of view.
DE 43 03 581 A1 describes an electrically insulating, gas-tight lead-through of at least one electrical conductor through a metallic casing of an exhaust system of an internal combustion engine. The lead-through is formed by two integral tabs, two consecutive sections being provided in the lead-through direction between them. In the first section, close to the exhaust system, the led-through metallic conductors are electrically insulated from the metallic tabs by a ceramic material, clay in particular. A permanently elastic plastic material is used in the subsequent second section as an electrical insulation and sealing material between the conductors and the tabs. DE 43 03 581 A1 thus addresses the problem of the gas-tight, electrically insulated lead-through of one or multiple electrical (metallic) conductors through a lead-through of an exhaust system formed by metallic tabs.
In contrast to the related art, the present invention provides a cost-effective and technically easy to manufacture, thermostable and liquid-tight joint between a first component, ceramic in particular, and a second component, metallic in particular, which may be exposed to an external medium and which reliably withstands rapid and frequent temperature changes (“temperature shocks”).